Snort document updates

A couple updates to SNORTⓇ installation guides for Snort 3 have hit our documentation page, and we want to take a minute and personally thank the community members that spend their time writing documentation, quality checking it, testing it, and putting it out there with their name attached to it — all in the interest of making the Snort community a better place.

So, thanks go to the following individuals:

• Noah Dietrich
• Yaser Mansour
• Milad Rezaei

First, we have an updated guide to Snort 2.9.14.1 on CentOS. This guide should work fine for our recently posted 2.9.15.0 release, simply by changing "2.9.14.1" to "2.9.15" where appropriate.

Next, there's an updated guide to Snort 3 installation on CentOS 8.

And we updated the guide to Snort 3 installation on Ubuntu 18 & 19.

As a reminder, our setup and installation guides can be found on Snort's documentation page under "Snort Setup Guides." While you are there, feel free to check out all the other documentation, such as Deployment Guides, startup scripts, and the official Snort manual.